a) Leaving group near the ring
The ring expels the leaving groups that are in a neighboring position, this position being attacked by the nucleophiles in the middle.
![derivatives pyrrole thiophene furan 01](/images/stories/heterociclos/pirrol-tiofeno-furano/se-furano/derivados-pirrol-tiofeno-furano-01.png)
The reaction takes place whether the chain is in position 2 or position 3.
![derivatives pyrrole thiophene furan 02](/images/stories/heterociclos/pirrol-tiofeno-furano/se-furano/derivados-pirrol-tiofeno-furano-02.png)
b) Carboxylic acids![pyrrole thiophene furan derivatives 03](/images/stories/heterociclos/pirrol-tiofeno-furano/se-furano/derivados-pirrol-tiofeno-furano-03.png)
Carboxylic groups in position 2 or 3 of the ring decarboxylate on heating
![pyrrole thiophene furan derivatives 03](/images/stories/heterociclos/pirrol-tiofeno-furano/se-furano/derivados-pirrol-tiofeno-furano-03.png)
c) Hydroxy derivatives![pyrrole thiophene furan derivatives 04](/images/stories/heterociclos/pirrol-tiofeno-furano/se-furano/derivados-pirrol-tiofeno-furano-04.png)
The keto form is more stable than the enol form in both positions 2 and 3.
![pyrrole thiophene furan derivatives 04](/images/stories/heterociclos/pirrol-tiofeno-furano/se-furano/derivados-pirrol-tiofeno-furano-04.png)
d) Carbonyls![pyrrole thiophene furan derivatives 05](/images/stories/heterociclos/pirrol-tiofeno-furano/se-furano/derivados-pirrol-tiofeno-furano-05.png)
The carbonyl group attached to the pyrrole ring is not very reactive towards nucleophiles due to the transfer of charge by the ring.
![pyrrole thiophene furan derivatives 05](/images/stories/heterociclos/pirrol-tiofeno-furano/se-furano/derivados-pirrol-tiofeno-furano-05.png)